I have a 2003 Jeep Liberty with 106,000 miles. I have noticed lately that the general sound that the vehicle makes going down the road is louder. It doesn’t seem to be engine-related, but related to the general speed of the vehicle. If step on the gas the noise doesn’t get louder with the engine, but it gets louder as the speed increases. It seems to be noticeable at any speed over 30-35 mph. Any guesses as to what it might be? I thought maybe it was tire-related, but they appear in good shape and are rotated regurally, unless my shop neglected to during the last oil change.
If the tires are the same ones it had when it was quiet, start checking bearings, u-joints, or even brakes.
My 91 Explorer developed a noise I told the mechanic might be a u-joint.
He replaced the rear axle outer pinion bearing.
Could still be the tires - -some tires get noisier as they wear.
Get up some speed and put it in neutral. That will eliminate the engine noise. Take care when doing this. Choose a low traffic time on a road where you’re likely to be able to hear things easily.
Anyway, sway the vehicle slightly left and right to see if the noise varies with the movement. Apply the brakes and see if the noise is altered. Not a panic stop, just a light application to see what changes.
Do a lower speed test on some empty parking lot where you might be able to hear the tires a bit better. There you would be a bit more extreme in the turning (circles, figure 8’s, etc).
I tried this and the noise didn’t change when put in neutral or when turning left and right. Applying the brakes didn’t affect anything- it sounds the same slowing down with the brakes applied or just slowing down by coasting.
Tires and shocks.